This invention relates generally to rotary vibrators and, more particularly, is directed toward an improved self-clamping vibrator-mounting bracket assembly.
Vibrators are used in various materials-handling applications such as for settling concrete and removing sand from foundry flasks. These applications typically involve large forms or molds wherein the vibrator is intermittently applied to various areas of the material to be agitated. An external vibrator securely mounted to the form or mold is preferred in such applications as internal vibrators are expensive to maintain and difficult to operate without degrading concrete quality and appearance. Ideally, an external vibrator should be relatively small and compact and capable of being securely and easily attached and removed without the use of complicated tools or an intricate and time-consuming procedure.
In addition, it is desirable for the vibrator to be self-locking thus obviating the need for conventional mounting means such as screws which generally must be continually tightened as they are subject to vibration loosening. The ideal rotary vibrator would also be free from the destructive effects of rust, corrosion and dust. In particular, the vibrator should not be susceptible of being contaminated with the material being vibrated which, in the case of concrete, generally results in damage to or destruction of the vibrator. Finally, the vibrator should be of a relatively simple design for increased reliability, ease of manufacture, and moderate cost.
U.S. Pat. No. 3,822,054, issued in the name of the present inventor, discloses a rotary vibrator having a generally tubular mounting structure within which a substantially circular vibrator casing is initially loosely fitted. The interior of the mount has one or more cam surfaces and the exterior of the casing has one or more cooperating cam surfaces. The rotation of the orbiting weight causes the casing in which it is located to undergo a migratory rotative movement in the same direction as that of the orbiting member. The migratory rotative movement of the vibrator's casing produced by the continuing driving force applied to the vibrator rotor causes the cam surfaces, or wedges, to inter-engage and continuously tighten so long as the driving force is applied. This three cam or deformed housing approach produces a relatively fast wedge or ramp shape. However, the angle of engagement between the casing and the mount is difficult to precisely control due to constant surface wear, flexibility of the housing, and surface distortion resulting from vibrator mounting. In addition, this configuration is not readily conducive to conventional fabrication and manufacturing processes because of the relative intricacy of the engaging surfaces.